Guardian television critic Stuart Heritage is in the kitchen this week to dispense some wisdom about celebrity interviews, Masterchef invention tests, and Spam. He calls Adam Richman a douche. Sam calls Christoph Waltz a motherfucker. James stares at Sam's hair a fair bit. Why is Sam hiding in Nigella's kitchen? Are Ben and Jerry Nazis? And just how much do Masterchef's John and Gregg loathe one another?